Upgrade Reek Dependency

[etagwerker]

Hey @dbwest @bf4,

This PR fixes #305 by bumping the dependency of reek and changing the implementation of reek's generator.

I tested that this works in this project: https://github.com/fastruby/e-petitions/tree/metric_fu

It now generates reek's report:

$ bundle exec metric_fu
******* STARTING METRIC churn
******* ENDING METRIC churn
******* STARTING METRIC reek
******* ENDING METRIC reek
******* STARTING METRIC saikuro
******* ENDING METRIC saikuro
******* STARTING METRIC flog
...

Please check it out.

Thanks!

[etagwerker]

@bf4 After debugging the Appveyor failure, it seems that I'd have to continue upgrading other dependencies. Not sure if that is a good idea, as this PR will continue to grow in size. I had to merge #308 inside this PR in order to get most of the builds to pass.

What do you suggest?

[bf4]

Generally changes look fine, but I'd recommend splitting up this PR into the necessary changes and other things you want to do while here to keep it simple

[etagwerker]

@bf4 Good point. I'll try to extract some of the changes into separate pull requests. Here is the first one: #310

[bronzdoc]

@etagwerker can you rebase this PR? 🙂

[etagwerker]

@bronzdoc Sure, done 👍